Terms sourced from: http://iupac.org/publications/pac/67/10/1725/

"Nomenclature, symbols, units and their usage in spectrochemical analysis-IX. Instrumentation for the spectral dispersion and isolation of optical radiation (IUPAC Recommendations 1995)", Butler, L.R.P.;Laqua, K., Pure And Applied Chemistry 1995, 67(10), 1725